Safety and efficiency go hand in hand with MacGregor ‘Hippo’ fully  automatic twistlock

MacGregor’s DNV-approved fully automatic twistlock is enabling Hapag-Lloyd to load an extra  tier of containers onboard its A19-class vessels without compromising on safety.  

In an era when digital technology and data-driven processes dominate discussion on improving  container transport efficiency, it is sometimes easy to overlook the impact of something as simple  as the humble mechanical twistlock.  

Initially secured by hand, the humble twistlock has nonetheless developed alongside the evolving  demands for greater efficiency from the global container industry with innovation taking it from  purely manual to semi-automatic and, more recently, fully automatic operation.  

While semi-automatic twistlocks are popular for their proven safety and relative simplicity, fully  automatic solutions represent an increasingly attractive alternative thanks to the convenience and  superior efficiency they provide. According to the world’s leading classification society DNV, fully  automatic twistlocks can also play an important role in facilitating automated terminal operations,  and could help to improve safety in cargo loading and discharge.  

One such solution is MacGregor`s ACV-1 ‘Hippo’, which is a DNV-approved fully automatic  twistlock that exceeds classification standards while helping customers maximise their stowage  efficiency.  

Most fully automatic twistlocks on the market deploy a locking mechanism to secure the twistlock  in the container corner casting during loading and discharge. While several variations of locking  mechanism are available. “Hippo uses a wire-operated mechanism that is proven to keep crucial  pressure surfaces intact and thereby minimise the risk of slip-out. This makes MacGregor’s  solution the safest fully automatic twistlock in the industry,” explains Arto Toivonen, Sales  Manager, MacGregor.  

“At DNV we have seen the evolution of the twistlock mechanism as designers have worked to find  a fully automatic system that both safely secures containers and enhances loading and unloading  efficiency,” says Daniel Abt, Approval Engineer, DNV. “During our testing we found that the  MacGregor’s ACV-1 fully automatic twistlocks have a load-bearing capacity that almost doubles  the requirements in our rules for automatic twistlocks and perform equivalently to semi-automatic  systems in terms of their ability to limit the movement of container stacks during voyages. 

More cargo, less risk  

An operator’s choice of twistlock can also play a big role in determining how much cargo a vessel  can carry while maintaining safety standards and leading container shipping company Hapag Lloyd has opted to implement Hippo across its A19 class of 19,900-TEU vessels.  

“We always want to load more cargo, of course, but ensuring containers are secure on board the  ship takes precedence over adding another tier,” comments Miguel Saez, Fleet Innovation  Manager, Hapag-Lloyd. “If a container stack collapses, the threat to crew and the marine  environment is considerable, while there are also clear financial and reputational ramifications to  consider. Safety is therefore our number one concern in planning lashing systems.”  

A crucial consideration when assessing the safety of a lashing system is the gap – or vertical  clearance – a twistlock leaves between containers. MacGregor’s Hippo twistlocks restrict vertical  clearance to 12 millimeters in accordance with updated guidelines from DNV and other major  classification societies. This enables the A19 vessels to transport an extra tier of cargo, for a total  of around 600 additional TEUs per ship, with the same vessel plan and cargo mix – and, crucially,  no negative safety impact.  

“The additional cargo-carrying capacity we gain on board our A19-class ships by implementing  Hippo highlights the close interplay between safety and efficiency,” notes Mr. Saez. “It also results  in a quick return on investment, which made this project, despite its extensive scale, an easy sell  from a business perspective, too.”  

Forged for safety and sustainability 

Hippo’s performance is partly attributable to how the system is manufactured. MacGregor’s  twistlocks are forged rather than casted, creating a denser structure that provides high tensile  strength, durability, and resistance to extreme conditions. Forging also makes Hippo a greener  alternative to cast twistlocks, explains Toivonen.  

“Third-party testing confirms that our forging process reduces carbon dioxide emissions by around  40% compared to casting,” he says. For the A19 vessels, which we supplied with 25,000  twistlocks each, this will significantly reduce the carbon emissions at the manufacturing phase.  Hippo will also reduce the voyage carbon intensity by enabling the vessels to carry more  containers with the same amount of fuel consumed compared to before the upgrade. This aligns  with Hapag-Lloyd’s operational efficiency and sustainability objectives.”  

In addition, Hippo is easy to install and operate, while its maintenance-free design eliminates the  need for greasing, Toivonen adds.  

A partnership built on transparency and expertise  

Explaining Hapag Lloyd’s motivation for specifying Hippo twistlocks, Mr. Saez emphasises their  safety, efficiency, and sustainability benefits. He also points to MacGregor’s capacity to provide 

a comprehensive scope of supply, its understanding of Hapag-Lloyd’s operational requirements,  and the transparent, trust-based relationship the two companies share.  

“MacGregor offers a wide range of equipment needed for securing cargo – not just twistlocks but  also lashing bridges, loose lashing equipment, hatch covers, and more,” says Mr. Saez. “Projects  are expertly tailored to our specific needs, and we are free to ask questions, request changes,  and verify everything with DNV. Finding a partner who understands operational requirements as  well as they understand technical factors is difficult – but that’s exactly what we get with  MacGregor.”  

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